Yamamoto U.S. Pat. No. 4,500,504 and Kida U.S. Pat. No. 4,690,811 discloses heating a composition containing carbon powder, a source of SiO.sub.2 in powder form, an iron, nickel or cobalt catalyst and NaCl spacer to obtain silicon carbide whiskers. Yamamoto teaches homogeneous introduction of catalyst by utilizing silica gel as the source of SiO.sub.2 and immersing fine particles of it in aqueous solution of catalyst. Both patents rely on blending carbon particles and silicon source particles and sodium chloride is admixed or placed beneath the other raw materials. These procedures rely on solids/solids mixing which is difficult where large amounts are involved and do not maximize homogeneity.
Yamaguchi et al U.S. Pat. No. 4,410,502 discloses contacting carbon particles with a solution or sol of silicic acid to obtain homogeneity to obtain submicron sized particles rather than whiskers. This process has not been able to be adapted to whisker production.
Consideration has been given to use of silicon tetrachloride as a silicon source. It has heretofore been considered necessary to use silicon tetrachloride in a gas phase in the production of silicon carbide whiskers (See Pultz U.S. Pat. No. 3,161,473: Hough et al U.S. Pat. No. 3,433,725; Knippenberg et al U.S. Pat. No. 3,721,782; Japanese 49-9500; U.K. Patent Specification 1,111,925 and Kendall, J.T., et al, "The preparation of Pure Silicon Carbide," lnternational Congress of Pure & Applied Chemistry, 11th, London, 1947, pp. 171-175).